The present invention relates to a patch antenna and the applications thereof, and more particularly, to the patch antenna using a circular radiating metal plate having an opening, and to the wireless network apparatus applying the patch antenna.
With the advancement of communication technologies, the applications using communication technologies have also increased significantly, thus making the related products more diversified. Especially, consumers have more demands on advanced functions from communication applications, so that many communication applications with different designs and functions have been continuously appearing in the market, wherein the computer network products with wireless communication functions are the main streams recently. Moreover, with integrated circuit (IC) technologies getting matured, the size of product has been gradually developed toward smallness, thinness, shortness and lightness.
An antenna in the communication products is an element mainly used for radiating or receiving signals, and the antennas used in the current wireless products have to own the features of small size, excellent performance and low cost, so as to be broadly accepted and confirmed by the market. According to the locations where antennas are mounted, the antennas can be classified into two categories, which are a built-in type and an external type. For the sake of appearance and convenient utilization, the built-in typed antennas have gradually replaced the external-typed antennas. On the other hand, the surface mount technology (SMT) that is suitable for use in mass production has been quite matured. Hence, applying the surface mounting technology in installing antennas can greatly reduce the cost for packaging and connecting the same, so that the surface mounting technology has become one of the most popular design methods for the built-in type antennas.
According to different operation requirements, the functions equipped in the communication products are not all the same, and thus there are many varieties of antenna designs used for radiating or receiving signals, wherein a patch antenna is quite commonly used. In order to obtain an antenna with high gain and broadband operation, the distance between the base board and the radiating metal plate can be increased for promoting the radiation efficiency and the operation bandwidth of the antenna. Generally, the features of antenna can be known by the parameters of operation frequency, radiation pattern, return loss, and antenna gain, etc. Hence, the design of patch antenna has to simultaneously consider the factors of appropriate distance between the base board and the radiating metal plate, and good antenna features.
However, it is very difficult for the conventional patch antenna to simultaneously have the advantages of low cost, small size, high antenna gain, broad operation bandwidth and good radiation pattern, and also not easy to match the design of the housing mechanism, so that the applications of the conventional patch antenna are greatly limited. Moreover, the conventional patch antenna has larger second harmonic, which will cause electromagnetic interference (EMI).
Hence, there is an urgent need to develop a patch antenna for satisfactorily meeting the antenna requirements of small size, high gain, wide broadband, simple design, low cost and small second harmonic, etc., thereby overcoming the disadvantages of the conventional patch antenna.
In view of the invention background described above, since the conventional patch antenna cannot effectively satisfy the aforementioned antenna requirements; is not easy to match the design of housing mechanism; and has larger second harmonic, the applications thereof are thus greatly limited.
It is the principal object of the present invention to provide a patch antenna and the apparatuses using the patch antenna, thereby providing the antenna with smallness, thinness, shortness and lightness, wherein the surface mount technology can be used to install the antenna on a base board, so that mass production can be performed, and the product stability can be enhanced. The present invention further provides the patch antenna having smaller second harmonic for avoiding causing EMI.
It is the other object of the present invention to provide a patch antenna and the application systems thereof, for obtaining better antenna performance by simultaneously installing two antennas on a base board via the arrangement of antenna diversity.
In accordance with the aforementioned objects of the present invention, the present invention provides a patch antenna, wherein the antenna comprises: a base board, wherein a coated ground plane is formed on the lower surface of the base board; a radiating metal plate, which is a round plate having an opening; a metal supporting plate, of which one end is electrically connected to one side of the opening of the radiating metal plate and a feeding point is formed thereon, wherein the aforementioned side of the opening is not parallel to the other sides of the opening; a metal fixed plate, wherein one end of the metal fixed plate is electrically connected to the other end of the metal supporting plate, and the metal fixed plate is electrically installed on the base board; wherein there is a predetermined distance maintained between the base board and the radiating metal plate.
Further, the present invention provides a wireless network apparatus, wherein the wireless network apparatus comprises: a base board, having a radio frequency (RF) device, and the radio frequency device has an antenna output terminal used for transmitting signals between the radio frequency device and a wireless system, and a coated ground plane is formed on the lower surface of the base board; a first patch antenna, wherein the first patch antenna comprises: a first radiating metal plate, which is a round plate having a first opening; a first metal supporting plate, of which one end is electrically connected to one side of the first opening and a first feeding point is formed thereon, wherein the aforementioned side of the first opening is not parallel to the other sides of the first opening; a first metal fixed plate, wherein one end of the first metal fixed plate is electrically connected to the other end of the first supporting plate, and the first metal fixed plate is electrically installed on the antenna output terminal; wherein there is a first predetermined distance between the base board and the first radiating metal plate; and a second patch antenna, wherein the second patch antenna comprises: a second radiating metal plate, which is a round plate having a second opening; a second metal supporting plate, of which one end is electrically connected to one side of the second opening and a second feeding point is formed thereon, wherein the aforementioned side of the second opening is not parallel to the other sides of the second opening; a second metal fixed plate, wherein one end of the second metal fixed plate is electrically connected to the other end of the second supporting plate, and the second metal fixed plate is electrically installed on the antenna output terminal; wherein there is a second predetermined distance between the base board and the second radiating metal plate. Further, the wireless network apparatus comprises a housing having a convex hollow portion used for accommodating the base board to form a wireless network card.